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<h1 class="doctools_title">tcl::chan::halfpipe(n) 1.0.1 tcllib &quot;Reflected/virtual channel support&quot;</h1>
<div id="name" class="doctools_section"><h2><a name="name">Name</a></h2>
<p>tcl::chan::halfpipe - In-memory channel, half of a fifo2</p>
</div>
<div id="toc" class="doctools_section"><h2><a name="toc">Table Of Contents</a></h2>
<ul class="doctools_toc">
<li class="doctools_section"><a href="#toc">Table Of Contents</a></li>
<li class="doctools_section"><a href="#synopsis">Synopsis</a></li>
<li class="doctools_section"><a href="#section1">Description</a></li>
<li class="doctools_section"><a href="#section2">API</a></li>
<li class="doctools_section"><a href="#section3">Options</a></li>
<li class="doctools_section"><a href="#section4">Bugs, Ideas, Feedback</a></li>
<li class="doctools_section"><a href="#keywords">Keywords</a></li>
<li class="doctools_section"><a href="#category">Category</a></li>
<li class="doctools_section"><a href="#copyright">Copyright</a></li>
</ul>
</div>
<div id="synopsis" class="doctools_section"><h2><a name="synopsis">Synopsis</a></h2>
<div class="doctools_synopsis">
<ul class="doctools_requirements">
<li>package require <b class="pkgname">Tcl 8.5</b></li>
<li>package require <b class="pkgname">TclOO</b></li>
<li>package require <b class="pkgname">tcl::chan::events <span class="opt">?1?</span></b></li>
<li>package require <b class="pkgname">tcl::chan::halfpipe <span class="opt">?1.0.1?</span></b></li>
</ul>
<ul class="doctools_syntax">
<li><a href="#1"><b class="cmd">::tcl::chan::halfpipe</b> <span class="opt">?<b class="option">-option</b> <i class="arg">value</i>...?</span></a></li>
<li><a href="#2"><i class="arg">objectCmd</i> <b class="method">put</b> <i class="arg">bytes</i></a></li>
</ul>
</div>
</div>
<div id="section1" class="doctools_section"><h2><a name="section1">Description</a></h2>
<p>The <b class="package">tcl::chan::halfpipe</b> package provides a command creating
one half of a <b class="package"><a href="tcllib_fifo2.html">tcl::chan::fifo2</a></b> pair. Writing into such a
channel invokes a set of callbacks which then handle the data. This is
similar to a channel handler, except having a much simpler API.</p>
<p>The internal <b class="package"><a href="../../../../index.html#tcloo">TclOO</a></b> class implementing the channel
handler is a sub-class of the <b class="package"><a href="../virtchannel_core/events.html">tcl::chan::events</a></b> framework.</p>
</div>
<div id="section2" class="doctools_section"><h2><a name="section2">API</a></h2>
<dl class="doctools_definitions">
<dt><a name="1"><b class="cmd">::tcl::chan::halfpipe</b> <span class="opt">?<b class="option">-option</b> <i class="arg">value</i>...?</span></a></dt>
<dd><p>This command creates a halfpipe channel and configures it with the
callbacks to run when the channel is closed, data was written to it,
or ran empty. See the section <span class="sectref"><a href="#section3">Options</a></span> for the list of
options and associated semantics.
The result of the command is a list containing two elements, the
handle of the new channel, and the object command of the channel
handler, in this order.
The latter is supplied to the caller to provide her with access to the
<b class="method">put</b> method for adding data to the channel.</p>
<p>Two halfpipes with a bit of glue logic in the callbacks make
for one <b class="package"><a href="tcllib_fifo2.html">tcl::chan::fifo2</a></b>.</p></dd>
<dt><a name="2"><i class="arg">objectCmd</i> <b class="method">put</b> <i class="arg">bytes</i></a></dt>
<dd><p>This method of the channel handler object puts the data <i class="arg">bytes</i>
into the channel so that it can be read from it.</p></dd>
</dl>
</div>
<div id="section3" class="doctools_section"><h2><a name="section3">Options</a></h2>
<dl class="doctools_options">
<dt><b class="option">-close-command</b> cmdprefix</dt>
<dd><p>This callback is invoked when the channel is closed.
A single argument is supplied, the handle of the channel being closed.
The result of the callback is ignored.</p></dd>
<dt><b class="option">-write-command</b> cmdprefix</dt>
<dd><p>This callback is invoked when data is written to the channel.
Two arguments are supplied, the handle of the channel written to, and the data written.
The result of the callback is ignored.</p></dd>
<dt><b class="option">-empty-command</b> cmdprefix</dt>
<dd><p>This callback is invoked when the channel has run out of data to read.
A single argument is supplied, the handle of the channel.</p></dd>
</dl>
</div>
<div id="section4" class="doctools_section"><h2><a name="section4">Bugs, Ideas, Feedback</a></h2>
<p>This document, and the package it describes, will undoubtedly contain
bugs and other problems.
Please report such in the category <em>virtchannel</em> of the
<a href="http://core.tcl.tk/tcllib/reportlist">Tcllib Trackers</a>.
Please also report any ideas for enhancements you may have for either
package and/or documentation.</p>
<p>When proposing code changes, please provide <em>unified diffs</em>,
i.e the output of <b class="const">diff -u</b>.</p>
<p>Note further that <em>attachments</em> are strongly preferred over
inlined patches. Attachments can be made by going to the <b class="const">Edit</b>
form of the ticket immediately after its creation, and then using the
left-most button in the secondary navigation bar.</p>
</div>
<div id="keywords" class="doctools_section"><h2><a name="keywords">Keywords</a></h2>
<p><a href="../../../../index.html#callbacks">callbacks</a>, <a href="../../../../index.html#fifo">fifo</a>, <a href="../../../../index.html#in_memory_channel">in-memory channel</a>, <a href="../../../../index.html#reflected_channel">reflected channel</a>, <a href="../../../../index.html#tip_219">tip 219</a>, <a href="../../../../index.html#virtual_channel">virtual channel</a></p>
</div>
<div id="category" class="doctools_section"><h2><a name="category">Category</a></h2>
<p>Channels</p>
</div>
<div id="copyright" class="doctools_section"><h2><a name="copyright">Copyright</a></h2>
<p>Copyright &copy; 2009, 2019 Andreas Kupries &lt;andreas_kupries@users.sourceforge.net&gt;</p>
</div>
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